1. Field of the Invention
The present invention relates generally to media sensors and, more particularly, to a media sensor system for determining a print medium type based on characteristics of the print medium when vibrated.
2. Description of the Related Art
A conventional non-impact print device such as an inkjet printer prints indicia on a print medium with a certain associated ink volume and application rate. This ink volume and application rate must be adjusted in accordance with the print medium on which the indicia are being printed. For example, a print medium, such as paper, is durable, highly absorbent and dries quickly, and therefore only requires application of a relatively small amount of ink over a short period of time. However, a more fragile and less absorbent medium, such as a plastic overhead transparency, requires application of a large amount of ink for saturation purposes over a longer period of time to allow proper drying of the ink without associated puddling. Therefore, the ink volume and application rate associated with an overhead transparency differs significantly from that of paper.
Presently, a user can adjust the ink volume and application rate of a printer by utilizing a printer control software program that is typically stored at a personal computer. However, if the user inadvertently forgets to adjust the print medium type at the personal computer prior to printing, fragile media, such as the above-discussed overhead transparency, may be damaged during the printing process.
Although non-contact optical sensors are commonly implemented in the media-handling axis of printer hardcopy output devices for print media detection purposes, the sensors are incapable of detecting a transparent medium unless an opaque appliquxc3xa9 is attached to the medium. While the opaque appliquxc3xa9 enables an optical sensor to detect the transparent medium, it creates numerous interface problems, increases the cost of the print medium to the end user and only enables the optical sensors to detect the edge of the medium on which the appliquxc3xa9 is located.
In addition, the above-discussed non-contact optical sensors are also incapable of sensing different types of non-transparent media such as, for example, paper and photographic media. It is important for printing purposes to distinguish between the two types of media, as the photographic medium is stiffer than paper and is similar to the overhead transparency medium in that it has poor absorbency and wetting characteristics and therefore a low dot gain.
Therefore, what is needed is a system that is capable of automatically adjusting the ink volume and application rate of a print device based on detected print media characteristics regardless of the type of print medium being used.